Questions tagged [iterator]
An iterator is an object-oriented programming pattern which for the most part functions similarly to a pointer to an object inside a collection with the added ability to traverse through the collection in a defined manner, agnostic of the actual implementation or even object addresses in physical memory. Iterators may be further limited in particular traversal directions.
347
questions
3
votes
1answer
61 views
Aggregation on list forEach and maps improvals
I am using a function in a SpringBoot @RestController, with Lombok
This function is an intermediate result that permit me to do an aggregation between two classes.
This 2 classes are:
...
0
votes
1answer
65 views
c++ python like range function to use in for loops
It's a simple range function that works like python range and it is only a syntactic sugar for the usual for loop
if we want to operate on numbers in the range from 1 to 10 (1 ... 9) we use this code ...
7
votes
3answers
277 views
LINQ Extension methods MinBy and MaxBy
LINQ Extension
I present a LINQ method ArgBy that returns the item of a sequence that corresponds to the predicate specified. Two additional methods ...
8
votes
2answers
146 views
Doubly-linked-list implementation in C++
I am fairly new to C++ and have been trying to make a doubly-linked-list class that imitates std::list (though not all of it). I'd appreciate if someone can look at my code and let me know if I have ...
3
votes
2answers
60 views
A basic trivia app
The app grabs 10 questions from an API, displays them one by one with 4 multiple choice answers. These answers are clickable buttons that alert to whether the answer is correct or not. Finally the ...
7
votes
2answers
125 views
Python-style Generator in Java
I have implemented Python-style generators within Java. I might be reinventing the wheel here, but I feel that the ability to define a Generator with an anonymous class is the most flexible approach. ...
2
votes
1answer
42 views
C++ singly linked list with iterator
I have written a simple singly linked list in C++. I have previously had a data structure in an interview criticised for being too C-like (no iterators and using new/delete) instead of smart pointers. ...
2
votes
1answer
72 views
Add method to Ruby's Enumerable module that produces every nth element
The task is to enhance the Enumerable module with a method nth().
The method shall create a new list, which contains every nth-...
5
votes
0answers
93 views
General algorithm to calculate sums of all subsets of a given sequence of numbers
Background
A recent question Print sums of all subsets made its way to the Hot Network Questions list. The problem is easy:
Print sums of all subsets of a given set
Given an array of ...
5
votes
2answers
76 views
Filename sequencer with outdated C++
My path to learning C++ has been a rough one. Currently, I'm writing a project and my knowledge is very outdated. While I can write code that accomplishes the tasks required, I'd like to improve and ...
2
votes
2answers
50 views
Implementation of enumerate
I'm trying to implement the enumerate built-in using iterators. So far it works but for unordered objects, such as sets or dictionaries, I'm not sure if this implementation is considered valid, ...
5
votes
3answers
220 views
SkipLast of an IEnumerable<T> - Linq Extension
As my answer to this question, I came up with this solution:
...
4
votes
1answer
48 views
Using best practice with complex iteration
I'm new to Rust so I'm still learning how to use best practice in complex examples.
Below is some code I've used in one of my programs, a simple implementation of a standard neural network.
Here is ...
4
votes
1answer
113 views
Email Generator
I've made a email generator, that uses a HTML template and replaces keywords in the template with information taken from a database. I'm looking to see if there is a way to improve the coding.
...
3
votes
1answer
56 views
C function to fully consume a Python iterator
I was reading into the proper way to consume an iterator on this question as well as here and I notices there is no actual proper function for this that clearly explains itself.
Using:
...
4
votes
1answer
79 views
Iterable hashtable implementation in C
I'm just finished my version of iterable hashtable. I want to review code in general (code style, data structures, remarks about the algorithms) and I have some questions:
I don't know how to ...
1
vote
1answer
57 views
Replace values in R data frame according to values in other data frame
I would like to change row names values from a first data frame if these rows names are present in another data frame, and change it to a corresponding value (defined in the second data frame). I ...
3
votes
1answer
81 views
Most efficient way to loop through files using VBA Excel
I have a procedure for looping through all files in folders and subfolders starting at a folder which the user can select. The user can select both the source and target folder. I'm using Excel VBA ...
3
votes
0answers
35 views
Rust Iterator that correlates a slice with itself
In my effort to learn Rust I've tried implementing an Iterator that splits up a buffer in two halves, and correlates both halves by sliding them over each other with different positions (lags). You ...
2
votes
2answers
62 views
1
vote
1answer
65 views
Sequence for Pre-order traversal of Binary Trees
I wanted to make a Sequence that can do a pre-order traversal of Binary Tree. Doing so provides automatically unlocks wonderfully useful methods, like ...
5
votes
2answers
74 views
Simple linked list with two iterators
As part of the practice, I created minimalist linked list named SimpleList which can be iterated in two different ways: one element after another or by every second ...
20
votes
4answers
4k views
Count all vowels in string
For a homework assignemnt, I was asked to complete this CodeStepByStep problem. It's coded correctly and gave me a right answer. I'm just wondering if there's an easier way to solve this problem ...
1
vote
2answers
46 views
Combining arbitrary number of lists inside json
I have some JSON where each key stores an array, and I need to combine all those arrays into a single array. My current solution doesn't seem the most friendly to review, but without ...
2
votes
1answer
125 views
Speed up fast poisson disk sampling generator in Python
I wrote a generator class which implements Fast Poisson Disk Sampling algorithm in Python. I did some optimizations like, x ** 2 -> x * x, using unpacking ...
4
votes
3answers
107 views
Linked list implementation C++
I hope this is the right way of doing things: I've previously posted a request for a code review and gotten feedback. Now I have new improved code that I would like a code review on again. Old: C++ ...
5
votes
2answers
111 views
C++ linked list iterator implementation
I'm a first year computer engineering student and would appreciate feedback on some code.
I've created a linked-list with an iterator to be able to range for loops like: ...
3
votes
1answer
64 views
Optimizing quicksort
I created simple quicksort algorithm using iterators. I'm happy with implementation but not with its speed. Profiler tells me that the slowest operation here is ...
2
votes
2answers
79 views
JS to create Table data dynamically
The following codes generate table row dynamically. I wonder if there are better ways of generating the same data. Also instead of manually coding the heading and the table itself, is it possible to ...
1
vote
0answers
52 views
itertools.produce reduced and filtered
I need to generate list of all allowable test combination values of of actor, action and ...
11
votes
3answers
2k views
Decoding assembly instructions in a Game Boy disassembler
I am coding a game boy disassembler in C++. The program (simplified here) converts a vector of byte into an assembly instruction and print it.
To do so, it iterates through the vector of bytes (char)...
2
votes
1answer
22 views
Short analogue of Riffle[] accepting two blocks
I have an array of some elements that I need to loop through (i.e. execute some block A on each element) but between them I have also to "clean up" (block ...
1
vote
1answer
42 views
Merging (not removing) duplicated elements in a vector
There's a struct named Player containing name and stat:
...
2
votes
2answers
72 views
A Java Iterable over multiple arrays
GlueArrays is used for iterating over an array of arrays, and it looks like this:
Main.java
...
3
votes
2answers
83 views
Infinite and countdown counters
I'm refactoring my scheduler and for one of its triggers I need an endless counter that would automatically restart. Since this is a simple and very common task I don't want to ever have to implement ...
4
votes
3answers
95 views
My implementation of a for_each function that traverses a std::container by some step size integer N
As my answer to Iterating over an odd (even) elements only in a range-based loop, I wrote this function, with the following driver program and output:
...
4
votes
1answer
43 views
Rust version of basic functional prime stream - can this be made less clunky?
I'm looking at implementing the basic functional not-quite-Eratosthenes prime stream in Rust. I like to try it when I start learning a language.
Here's the bog standard Haskell version:
...
1
vote
1answer
114 views
Find all starting indices in a string which are anagrams of a word
The task:
Given a word W and a string S, find all starting indices in S which
are anagrams of W.
For example, given that W is "ab", and S is "abxaba", return 0, 3, and
4.
My solution:
...
2
votes
1answer
88 views
Iterating over different Objects which are ordered by index number
I am currently working on a bigger project where I found a part of it which seems very ugly to me from the code.
I stripped out the algorithm and made a working code, so it can be reviewed.
I have ...
1
vote
1answer
292 views
Applying multiple php FilterIterator instances in a cascading fashion
I wrote an implementation of php FilterIterator objects that allows me to apply them in a "cascade" way, so I can finally obtain an array of objects which is the ...
0
votes
0answers
60 views
An iterator returning all possible permutations of a list in Java - follow-up
(See the previous and initial iteration.)
My main attempt here was to get rid of monolithic code and split the implementation into smaller methods when applicable and do more extensive commenting. ...
5
votes
3answers
546 views
Python generator for “barely obtuse” triangles (Project Euler 224)
I am trying to solve Project Euler Problem 224:
Let us call an integer sided triangle with sides a ≤ b ≤ c barely obtuse if the sides satisfy a2 + b2 = c2 - 1.
How many barely obtuse triangles ...
4
votes
2answers
84 views
Python grouped iterator
I wanted to write an iterator that would split items up into groups, so i can bulk insert into mysql without crashing or overwhelming the server.
This is the implementation I came up with.
I am ...
2
votes
0answers
41 views
Iterator that groups elements of its source
I wrote an iterator to access the pixel in an packed image.
It works, but it is slow.
1.Are there any mistakes that can be avoided and might lead to better speed?
2.Are there any pitfalls that ...
2
votes
1answer
53 views
Class representing digital PLC address
I have a project where I work with digital addresses for a Programmable Logic Controller (PLC). The requirement is that the user gives a start address e.g. 1000.0 and then for example the next 20 ...
4
votes
2answers
118 views
Finding the common iterator category in C++
I created a template trait which finds the common iterator category between a set of given iterator categories. More specifically, it's a class with a member type alias to one of the iterator tags ...
2
votes
1answer
35 views
Finding the Original Fractions from Rounded Decimals
The data I'm using is summoning rates from a gacha game, One Piece Treasure Cruise. The game provides the probability of getting a certain character in percents rounded to the nearest thousandth. ...
6
votes
2answers
167 views
Walking directory tree like python does
I like python's os.walk and I was missing it in C#. It's a very convenient API so I thought I create my own utility that does something similar.
The original API ...
4
votes
1answer
304 views
back_inserter for several container arguments
Recently I wrote a back_inserter with the same interface as the std::back_inserter just for supporting several containers in the constructor and doing push_back for each. The solution needs C++17. ...
1
vote
1answer
69 views
Convert a type u16 number to a matrix (Vec<Vec<u8>> or array) of 4 x 4
I am a Rust newbie and I am not familiar with all the iterator options. This is what I have so far. How can I make this better or at least avoid collecting twice into a Vec?
...
